SEPTIC SYSTEMS... CARE AND FEEDING

A few months ago, I asked my longtime friend Ralph Stanton... superhero soil
scientist, civil engineer, and sanitarian... to give me some information about
septic systems from the view of a professional, as opposed to my views, which
are those of an end user (pardon the pun). I had received a number of requests
from my readers, and, though I always have something to say on any home repair
topic, this was one subject of which I had only the most meager knowledge. Well,
that has all changed. So if you want to know more than you ever thought you
needed to know about septic systems, it's all here.

Keep in mind that the requirements for septic systems vary throughout the
world. That which is acceptable in some areas is prohibited in others. So, take
this for what it is... a primer to increase your general knowledge of how these
systems work, how they fail, and how to protect your investment.

REMEMBER... you can flush anything, including your spouse, your career, or
your reputation down the toilet. Just don't complain to me when it comes back to
haunt you!

WHAT IS A SEPTIC SYSTEM?

A Septic system is simply an onsite subsurface sewage disposal system for
your home. It takes household sewage wastes and discharges the liquid portion to
the ground. Septic systems are a standard method of sewage disposal in rural and
suburban areas where centralized sewer treatment plants are not available, not
affordable, or not desired. A properly designed and installed septic system with
regular cleaning and maintenance of the septic tank can last indefinitely and be
the most cost effective and least labor intensive method of sewage disposal.

In its most basic form a gravity Septic System consists of a Septic Tank
connected by solid pipe to some type of leaching system.

If you would like to view a diagram of a typical Septic System, click HERE

Septic Tank...

The septic tank is a large tank of usually 1000 gallon capacity or more. The
size is generally based on the number of bedrooms which denote a certain amount
of water usage per day. Today the tank is generally constructed of concrete,
plastic or fiberglass and is designed to be water tight. Click HERE
to view a typical septic tank

The function of the septic tank is basically as a settling tank and/or
clarifier. Most of the work done in the tank is settling. Some decomposition
goes on with the sludge but it is usually very slow because the temperature is
relatively low and due to the general lack of oxygen in the sludge mass, the
process becomes mainly anaerobic-septic (methane and hydrogen sulfide compounds
are created - rotten egg smell), hence the name Septic Tank.

In action the septic tank can be thought of as a corporate or political
organization. The masses enter the tank (liquids and solids) by dropping through
the inlet pipe/ baffle. The (lazy) heavier particles sink to the bottom
(according to Stoke's Law) and become the sludge, some particles, grease, and
gas rises to the top of the liquid as the (leaders-executives) scum. The main
body of water circulates through the tank and then flows out the outlet pipe and
baffle. This water is normally gray in color because of the fine particles that
stay suspended (the silent majority) and are carried out to the leaching system.

The Leaching System

The LEACHING SYSTEM may consist of perforated PVC (plastic) pipe set in clean
1.25 inch diameter stone in trenches a 1 - 4 feet wide and 1.5 feet deep, or
some type of gallery structure (a hollow concrete or plastic structure with an
open bottom).

After the careful analysis of the soils by an experienced Soil Scientist,
Professional Engineer or Registered Sanitarian, the type of leaching system is
determined. The leaching system, if conditions allow, will be placed in the
upper part of the subsoil known as the Bw horizon. The reason we place the
leaching system into the upper part of the subsoil is that this horizon is where
there oxygen is plentiful and the biological activity is greatest (excluding the
top soil or A horizon).

Unlike the septic tank, the leaching system to be most effective must operate
in aerobic conditions (with oxygen present). Therefore the septic effluent
leaving the leaching system entering the subsoil will acted upon by the aerobic
soil bacteria to “treat” it or remove the pathogenic bacteria and viruses
and some of the chemical nutrients. If there is ground water or some restrictive
condition (dense glacial till [mixed sand, silt, gravel and clay] or
bedrock-ledge) the leaching system must be kept elevated above (according to
local health codes) a certain number of feet. This is done to prevent: unwanted
partially treated sewage effluent from directly entering the bedrock or directly
entering the ground water and possibly contaminating a nearby water supply well.

Also if a restrictive layer is directly beneath the leaching system the leaching
system will tend to stay mounded with water in it and after a while it will
become anaerobic (once the oxygen has been used up) then the system will fail.
When these soil conditions are found the experienced Soil Scientist,
Professional Engineer or Registered Sanitarian will often call for the use of a
Uniform sand fill to elevate the leaching system (providing the existing subsoil
can support or handle the volume of sewage effluent being discharged). That is
why many of the new and repair septic systems designed and installed today are
in sand mounds.

WHY SEPTIC SYSTEMS FAIL

If the partially treated sewage effluent from the septic tank cannot soak
into the soil surrounding the leaching system, sewage may back up in the system
and overflow into the house or puddle on the surface of the ground. There are
several possible causes of this problem.

1. POOR SOIL CONDITIONS

A leaching system placed in unsuitable soil, or a system too small for the
house it serves or not properly constructed may lead to early failure. In most
cases it will be necessary to install a new system to correct the condition.

2. SOIL CLOGGING

If sludge or from the septic tank is allowed to escape into the leaching
system, the leaching system / soil interface will quickly become clogged and
form a barrier to further penetration by effluent This condition can be caused
by: broken baffles which allow the sludge to flow out of the tank, or failure to
pump the septic tank out on a regular basis (2-5 years for a tank that meets the
code) causing sludge buildup in the tank to the point where it washes over the
baffles.

3. HIGH WATER TABLE

During wet seasons the groundwater table can rise into the leaching system
area and sewage may be forced upward to the ground surface. This problem is
usually the result of improper installation and can be corrected by relocating
or raising the leaching area at least eighteen inches above the maximum high
water-table. Another possible solution is to install ground water drains around
the leaching area to lower the groundwater table if slope and soil conditions
warrant.

4. TREE ROOTS

The roots of trees and bushes planted too close to the leaching area can
sometimes enter and block the pipes of the system. removal of such plants is
usually required.

5. HEAVY WEIGHTS OVER ANY PART OF SYSTEM

Trucks or heavy equipment passing over the tank or leaching system area can
so damage connections, crush pipe and or compact the soil as to render the
entire system inoperable. Being aware of the location of all elements of the
system and directing traffic around them can prevent such damage.

DOS AND DON'TS TO KEEP YOUR SEPTIC SYSTEM HEALTHY

By following a few simple rules and procedures, the homeowner can help save
his system against premature failure.

DOs

Establish accurate records of the location and cleaning of the system.

Set up and follow a system of inspection and pump outs. A septic
tank should be pumped out every two to five years, depending on usage and
conditions. While the tank is being pumped out make sure the operator
inspects both baffles of the tank (as required by the Connecticut State
Health Regulations). If either baffle is broken, have it repaired
immediately. The cost of replacing a defective baffle is far less than the
cost of replacing a leaching system that has been ruined.

Minimize water use in the home and teach children water conservation.
Excessive quantities of water will reduce the effectiveness of the septic
tank and lead to flooding of the leaching are. Use low-flush toilets because
40% of all family water use falls in this category. A toilet dam (a
block/brick to take up water space [in old toilets]) placed in the water
tank will reduce water use with each flush. Repair dripping faucets and
running toilet mechanisms. Install water-saving shower heads and aerators on
all faucets. Spread laundry out the week, don't do it all in one day (but
don't run the washing machine with less than a full load).

DON'TS:

DO NOT put the following materials in your septic system:

Septic system additives meant to correct a malfunctioning system or
improve its performance. This includes: degreasing agents, caustic
chemicals, solvents and bacterial digestion enhancers such as enzymes or
yeast. At best they do little, at worst they can be dangerous and can impair
the natural bacterial activity of the system. Many chemicals are not
biodegradable and will pass through the system and soil and then into the
ground water where they can potentially contaminate well water. You could
render your own or you neighbor's well water unfit to use.

Automotive oil, gasoline or any motor fuels or coolants (anti-freeze) in
any quantity, should NEVER be disposed of in the septic system.

Salt brine backwash water/solution from a water softener should NEVER be
discharged into the septic system.

Pesticides, disinfectants, acids, medicines, paint, paint thinners,
grease, solvents, these wastes are hazardous, should be used with caution
and NEVER be disposed of into the septic system because they will
contaminate the soil, ground water and possibly your own or you neighbor's
well.

Coarse organic matter such as vegetable trimmings, ground-up garbage (sink
garbage disposals should never be utilized on a septic system),
condoms sanitary napkins, disposable diapers, coffee grounds, paper towels,
etc. will over load the septic tank with sludge and floatables and will at
the very least make for more frequent pumping

Cooking oils, liquefied meat fats (bacon grease) may pass through the
septic tank and as they cool, solidify and clog the leaching fields. ALWAYS
Dispose of the fats and greases in a container in the house hold garbage.

MODERATE AMOUNTS of bleach and other
household cleaners will not significantly interfere with the septic system's
bacterial processes.

SPECIAL NOTE: DO NOT dig up an existing septic leaching system unless there is
insufficient space to install a new system or expand the present one.

Before purchasing raw land or an existing property
with a septic system...

It is my recommendation that you contact the local health department before
purchasing: raw land to be developed for your dream house or business, or before
purchasing an existing home or business that is using a septic system. They can
provide you with information about the existing septic system and whom locally
can do soil testing to provide you with a feasibility report on the property
with regard to its ability to support a septic system on that property for the
use you intend for it.